The present invention consists in a torque variator device which, applied to transmission shafts, allows varying the torque applied when said shafts are functioning; applied to differential gears of vehicles allows to vary the torque of a palier respecting the other palier.
There are different moments and circumstances in which the transmission shaft of a mechanism requires a greater torque than the used normally. Such is the case in the starting step of some mechanisms in which forces liable to overcome the tendency of the set at rest are required. This tendency becomes evident more acutely during the starting step, but, up to certain extent, it can become evident later during other steps of the normal regime. In these cases, the highest torque is tried to be achieved, delivering the least amount of energy possible.
These needs may be satisfied by means of the present toque variator device which is disposed interconnected between the conducting and conducted ends of the application shaft. It includes a conducting piece with radial throat that are used as guides to articulated arm components of a set radially expandable that, in its position of maximum expansion, allows to obtain the maximum torque.
In order to vary the torque, the device counts with a positional variator that, provided with control means, realizes the expansion or contraction of the expandable set. Thus, the torque is varied, which, through the conducted piece is delivered to the conducted end of the application shaft.
A typical case of application is in the paliers (bearings) of vehicles. As is known, these paliers are projected as from the output of the differential gear. In the curves of the road, the external wheel must travel a longer arch, the latter has the function of allowing the same to turn faster than the internal wheel. The drawback is that, in traditional differential gears, the external wheel that turns faster decreases its power allowing problems concerning stability and grip, particularly in difficult or badly maintained roads.
In order to limit this problem one turns to device such as the so called Torsen system which is based in a plurality of helicoidal screws disposed in the satellite pinions. Nevertheless, this system has its limitations as its wearing out gives place to blockage or skidding.
The so called viscous couplings are also employed, which are composed by an alignment of friction discs which are affixed one to another, being immersed in oil. In this case the wearing out or oil leaking produced to same abovementioned unwanted effects.
Instead, with the present torque variator device there is a solution for all these drawbacks, as, not only the mentioned wearing out is prevented, but also the torque of a palier may be varied with respect to the torque of the other, varying it according to the requirements of each wheel, particularly in the curves.
Thus, by means of the radial expansion of the expandable set, the articulated arms are shifted towards the periphery of the conducted piece, obtaining a greater toque over the conducted end of the wheel which is external in the curve. At the same time, by means of the contraction of the expandable set of the other palier, the torque of the internal wheel is decreased in the curve, thus obtaining an optimum functioning of the vehicle even on difficult roads.
On the other hand, the presence of control means as a pneumatic device allows to carry out the control an the operation of the device by means of any compatible commanding device, such as an electronic circuit drive.